1. Field of the Invention
The present invention relates to an electrically controlled clamping device for a system for adjusting the position of a first member relative to a second member regarded as fixed. The clamping device has a clamping axis substantially perpendicular to the axis of the first member. The clamping device for a position adjustment system is applicable in particular to a steering column of an automobile vehicle, the steering column being adjustable in height and/or in depth in the vertical plane.
2. Description of the Prior Art
There are steering columns which can be adjusted in height or in depth, or in height and depth, which have a system for adjusting the steering columns relative to a support member joined to the bodyshell of the automobile vehicle. The position adjustment system is provided with a clamping device with two positions: an unlocked position to enable adjustment of the steering column to the required position, and a locked position once that position has been chosen.
In prior art systems, the clamping device of the system for adjusting the steering column of the automobile vehicle has a clamping rod axis below the first member or body-tube of the steering column. The clamping device has an operating handle and a locking system, for example using cams, disposed at one end of the clamping rod. The clamping rod passes through the two uprights of the second member which is regarded as fixed.
This type of assembly has overall dimensions that are inconvenient for the driver and above all dangerous in the event of an accident because it requires a clamping rod disposed very low down under the steering column with an operating handle that can impact on the driver's body in the event of an impact.
Accordingly, the present invention was developed to provide a clamping device which avoids the drawbacks described above and whose operating system can be disposed away from the environment of the steering column so as to free up the area below said steering column.
A primary object of the present invention is to provide a clamping member has an inverted U-shaped configuration including a horizontal base portion and a pair of vertical parallel spaced downwardly depending leg portions between which the first member is pivotally mounted on a clamping rod. Clamping means are provided for displacing the leg portions together in clamping engagement with the first member, thereby to clamp the first member in a given position of angular adjustment relative to the fixed support member. In a first embodiment, the clamping means includes a pair of collinearly arranged disk-shaped cam members coaxially mounted on the stationary clamping rod, the adjacent faces of the cams being provided with cam teeth that axially separate the cam disks when the cam disks are rotated relative to each other, whereby the leg portions of the fixed support are displaced toward each other to clamp the movable member therebetween. In a second embodiment, a clamping nut is threadably mounted on the stationary clamping rod for forcing the legs together into clamping engagement with the movable member.
The clamping device includes a cam-type immobilizing system arranged outside one of the uprights relative to the axis of the first member, between an outside face of said upright and a bearing member joined and substantially perpendicular to the clamping rod.
In accordance with a further object of the invention, it is particularly beneficial to provide a system supplying information on the locked or unlocked status of said clamping device, which is triggered by remote control of the electromechanical energy converter.
According to another object of the invention, speed reducer means are provided for driving the cam means from electromechanical energy converter means.
In one variant of the invention, the clamping reducer and the electromechanical energy converter form a single system and the clamping reducer is free to rotate on the clamping rod.
In another variant of the invention, the clamping reducer and the electromechanical energy converter are rotationally linked by a mechanical motion transmission system so that the electromechanical energy converter can be placed at the required location and the clamping reducer is free to rotate on the clamping rod.
In the latter case, the mechanical motion transmission system is a flexible cable in a sheath supported at one end by the electromechanical energy converter and at the other end by the casing of the clamping reducer.
In another type of embodiment, the speed reducer system includes two speed reducers:
a speed reducer referred to as the clamping reducer which drives rotation of the clamping device and is mounted to rotate freely on the clamping rod; and PA1 a speed reducer referred to as the converter reducer which is driven directly by the electromechanical energy converter.
In one variant of the invention, the clamping reducer, the converter reducer and the electromechanical energy converter form a single system and the clamping reducer is free to rotate on the clamping rod.
In another variant of the invention, the clamping reducer, on the one hand, and the converter reducer with
In another case, the electromechanical energy converter is remotely controlled by the ignition key of the automobile vehicle.
In accordance with the invention, the system
In accordance with the invention, one embodiment of the clamping reducer and the immobilizing system is achieved as described hereinafter. In this embodiment, the clamping device includes a clamping rod with a nut which is locked or unlocked by an electrical remote control system.
The clamping rod has a bearing member joined to and substantially perpendicular to the clamping rod outside one of the uprights and against an outside face of that upright. Said clamping rod is prevented from rotating about the clamping axis by the bearing member. The clamping rod has at its other end a screwthreaded part which cooperates with the nut which is outside the other upright. The nut is locked or unlocked by the electrical remote control system.
The bearing member is the nut mounted and screwed
A particularly beneficial application of the invention is to an automobile vehicle steering column in which the first member is the body tube with its reinforcing bracket and the support member is mounted on the bodyshell of the vehicle.
The electrically controlled clamping device of an automobile vehicle steering column in accordance with the invention therefore has the advantage of having an operating system that is outside the immediate environment of the steering column, which frees up the area below the steering column. Also, this remotely controlled clamping device can easily be fitted to existing steering columns.